Interannual Sea Level Variability Along the Southeastern Seaboard of the United States in Relation to the Gyre‐Scale Heat Divergence in the North Atlantic

Abstract

AbstractThe low‐amplitude, large‐scale, interannual, and longer‐term sea level changes are linked to the variations of ocean heat and freshwater content and strongly controlled by ocean dynamics. Near the coast, especially in low‐lying and flood‐vulnerable regions, these changes can provide background conditions favorable for the occurrence of extreme sea levels that represent a threat for coastal communities and ecosystems. In this study, we identify a tripole mode of the ocean gyre‐scale sea surface height variability in the North Atlantic and show that this mode is responsible for most of the interannual‐to‐decadal sea surface height changes along the southeast coast of the United States, including the Gulf of Mexico. We also show that these changes are largely driven by the large‐scale heat divergence related to the Atlantic Meridional Overturning Circulation and linked to the low‐frequency North Atlantic Oscillation.